This invention relates to polymer latices which have wide utility as adhesives, coatings, textile sizes, packaging films, and the like. The polymers are also useful as binders in the textile, leather and paper industries, and as intermediates or ingredients in the production of synthetic resin systems for coating, molding and casting applications. In more detail, this invention relates to polyurethane polymer latices which are prepared by the incorporation of polyethylene glycol, within defined limits, into the backbone of a polyurethane polymer.
The use of polyethylene glycol(s) as a polyol constituent in the preparation of polyurethane polymers, usually in conjunction with other polyalkylene glycols or polyesters, has been known for some time. However, because of their hydrophilicity, polyethylene glycols are not a favore ingredient of polyurethanes since their presence tends to impart water sensitivity to the polyurethane polymer. Indeed, when a substantial proportion of a polyethylene glycol is used in a polyurethane, the resultant polyurethane may be water soluble. If a water soluble or water dilutable polyurethane incorporating polyethylene glycol is desired, all or a substantial portion of the polyol component of the polymer would necessarily be polyethylene glycol. Alternatively, polyethylene glycols are generally avoided in preparing water insoluble polyethylene glycols are generally avoided in preparing water insoluble polyurethanes since even small amounts would impart a significant degree of water sensitivity to the polymer. Whatever advantageous properties polyethylene glycols may serve to contribute to the polymer can be obtained ordinarily with the use of hydrophobic polyalkylene glycols which would not affect the water sensitivity of the polymer. In view of the known effects of incorporating polyethylene glycol in polyurethane polymers, it is surprising that its use in specified and critical amounts imparts emulsifiability to an otherwise water insoluble polymer.
It is the object of this invention to provide useful polyurethane polymer latices of non-ionic character which can be used as adhesives, coatings, binders, saturants, and the like.
It is another object of this invention to provide useful polyurethane polymer latices which possess an anionic or cationic character and which can be used as adhesives, coatings, binders, saturants, and the like.
A further object is to provide a process for the production of these non-ionic or cationic polyurethane latices.
Another further object is to provide polyurethane polymers in an aqueous medium, free from toxic and photochemically active organic solvents.
Other objects of this invention will be apparent to those skilled in the art to which this invention pertains.